The present invention relates to an engine control system and, more particularly, to an engine control system suited for controlling acceleration of an engine having a mechanical fuel injection device.
A so-called mechanical fuel injection apparatus for mechanically controlling a fuel injection rate on the basis of motion of a plate disposed in an intake air passage is well known, as is disclosed in Japanese Patent Laid-Open No. 55-46096 (1980).
The prior art described above takes no consideration into operations during acceleration. Even if a throttle valve for control of intake air flow is opened for acceleration, a fuel injection rate, for example, is not promptly increased due to delay in response to a mechanical system so that the fuel is not augmented with the increase in the intake air flow. As a result, the air/fuel ratio is shifted to the lean side resulting in reduced torque, but this torque is then abruptly raised to produce acceleration shocks so that hunting occurs after the acceleration.